1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_UTF_OFFSET_STRING_CONVERSIONS_H_ 6 #define BASE_UTF_OFFSET_STRING_CONVERSIONS_H_ 7 #pragma once 8 9 #include <string> 10 #include <vector> 11 12 #include "base/base_api.h" 13 #include "base/string16.h" 14 15 namespace base { 16 class StringPiece; 17 } 18 19 // Like the conversions in utf_string_conversions.h, but also takes one or more 20 // offsets (|offset[s]_for_adjustment|) into the source strings, each offset 21 // will be adjusted to point at the same logical place in the result strings. 22 // If this isn't possible because an offset points past the end of the source 23 // strings or into the middle of a multibyte sequence, the offending offset will 24 // be set to std::wstring::npos. |offset[s]_for_adjustment| may be NULL. 25 BASE_API bool UTF8ToWideAndAdjustOffset(const char* src, 26 size_t src_len, 27 std::wstring* output, 28 size_t* offset_for_adjustment); 29 BASE_API bool UTF8ToWideAndAdjustOffsets( 30 const char* src, 31 size_t src_len, 32 std::wstring* output, 33 std::vector<size_t>* offsets_for_adjustment); 34 35 BASE_API std::wstring UTF8ToWideAndAdjustOffset(const base::StringPiece& utf8, 36 size_t* offset_for_adjustment); 37 BASE_API std::wstring UTF8ToWideAndAdjustOffsets( 38 const base::StringPiece& utf8, 39 std::vector<size_t>* offsets_for_adjustment); 40 41 BASE_API bool UTF16ToWideAndAdjustOffset(const char16* src, 42 size_t src_len, 43 std::wstring* output, 44 size_t* offset_for_adjustment); 45 BASE_API bool UTF16ToWideAndAdjustOffsets( 46 const char16* src, 47 size_t src_len, 48 std::wstring* output, 49 std::vector<size_t>* offsets_for_adjustment); 50 51 BASE_API std::wstring UTF16ToWideAndAdjustOffset(const string16& utf16, 52 size_t* offset_for_adjustment); 53 BASE_API std::wstring UTF16ToWideAndAdjustOffsets( 54 const string16& utf16, 55 std::vector<size_t>* offsets_for_adjustment); 56 57 // Limiting function callable by std::for_each which will replace any value 58 // which is equal to or greater than |limit| with npos. 59 template <typename T> 60 struct LimitOffset { LimitOffsetLimitOffset61 explicit LimitOffset(size_t limit) 62 : limit_(limit) {} 63 operatorLimitOffset64 void operator()(size_t& offset) { 65 if (offset >= limit_) 66 offset = T::npos; 67 } 68 69 size_t limit_; 70 }; 71 72 // Adjustment function called by std::transform which will adjust any offset 73 // that occurs after one or more modified substrings. To use, create any 74 // number of AdjustOffset::Adjustments, drop them into a vector, then call 75 // std::transform with the transform function being something similar to 76 // AdjustOffset(adjustments). Each Adjustment gives the original |location| 77 // of the encoded section and the |old_length| and |new_length| of the section 78 // before and after decoding. 79 struct AdjustOffset { 80 // Helper structure which indicates where an encoded character occurred 81 // and how long that encoding was. 82 struct Adjustment { 83 Adjustment(size_t location, size_t old_length, size_t new_length); 84 85 size_t location; 86 size_t old_length; 87 size_t new_length; 88 }; 89 90 typedef std::vector<Adjustment> Adjustments; 91 92 explicit AdjustOffset(const Adjustments& adjustments); 93 void operator()(size_t& offset); 94 95 const Adjustments& adjustments_; 96 }; 97 98 #endif // BASE_UTF_OFFSET_STRING_CONVERSIONS_H_ 99